Changes in liver and spleen volumes after living liver donation: a report from the Adult-to-Adult Living Donor Liver Transplantation Cohort Study (A2ALL)

Imaging Evaluation of the Living Liver Donor: A Systems-Based Approach

Liver transplant is the definitive treatment of end-stage liver disease and early hepatocellular carcinoma. The number of liver transplant surgeries done is highly affected by the number and availability of deceased donor organs. Living donor liver transplantation has emerged as an alternative source of donors, increasing the availability of organs for transplant. Many factors must be considered when choosing living donor candidates to maintain a high level of donor safety and organ survival. To that end, potential donors undergo a rigorous pre-donation workup.

Medical-ethical guidelines: Living donation of solid organs

No abstract available.

Fibroprogression and Cirrhosis Occurring in Living Liver Donor: First Case Report

Background

Limited dead donor pool paved the way for living liver donation so that waitlist mortality could be reduced. With over two decades of experience in the East as well as in the West, right lobe adult-to-adult living donor liver transplantation has become an established intervention. The short-term surgical outcomes, complications and health-related quality of life are well known. There is dearth of data on long-term health of remnant liver of donors, especially after a decade of donation.

Case description

A 56-year-old lady who donated her right liver lobe 11 years back for her husband with end-stage liver disease. Recipient is doing well till date. She was incidentally found to have thrombocytopenia on follow-up. Her haematological evaluation was negative for blood dyscrasias. Further evaluation demonstrated biopsy-proven cirrhosis with endoscopic evidence of portal hypertension. Aetiological workup was done, which ruled out viral, autoimmune causes as well as Wilson's disease and hemochromatosis. This donor had gained weight post-donation with body mass index of 32.4 kg/m2 and dyslipidaemia. The final diagnosis of fibro progression due to non-alcoholic fatty liver disease was made.

Conclusion

We report the first case of cirrhosis developing in a right lobe living liver donor. While selecting living liver donors, extensive evaluation is done to rule out all potential aetiologies remaining silent but later could lead on to chronic liver disease. Although all other aetiologies, which could induce inflammation and fibrosis, are ruled out at the time of donation, lifestyle liver disease, especially non-alcoholic fatty liver disease, can occur in remnant liver post-donation. This case underscores the importance of regular follow-up of liver donors.

Pregnancy Outcomes After Living Liver Donation: A Multi-Institutional Study

Nearly half of living liver donors in North America are women of child-bearing age. Fetal and maternal outcomes after donation are unknown. We conducted a retrospective cohort study of female living liver donors (aged 18-50 years at donation) from 6 transplant centers. Participants were surveyed about their pregnancies and fertility. Outcomes were compared between predonation and postdonation pregnancies. Generalized estimating equations were clustered on donor and adjusted for age at pregnancy, parity, and pregnancy year. Among the 276 donors surveyed, 151 donors responded (54.7% response rate) and reported 313 pregnancies; 168/199 (68.8%) of the predonation pregnancies and 82/114 (71.9%) of the postdonation pregnancies resulted in live births, whereas 16.6% and 24.6% resulted in miscarriage, respectively. Women with postdonation pregnancies were older (32.0 versus 26.7 years; P < 0.001) and more frequently reported abnormal liver enzymes during pregnancy (3.5% versus 0.0%; P = 0.02) and delivery via cesarean delivery (35.4% versus 19.7%; P = 0.01). On adjusted analysis, there was no difference in cesarean delivery (odds ratio [OR], 2.44; 95% confidence interval [95% CI], 0.98-6.08), miscarriage (OR, 1.59; 95% CI, 0.78-3.24), combined endpoints of pregnancy-induced hypertension and preeclampsia (OR, 1.27; 95% CI, 0.36-4.49), or intrauterine growth restriction and preterm birth (OR, 0.91; 95% CI, 0.19-4.3). Of the 49 women who attempted pregnancy after donation, 11 (22.5%) self-reported infertility; however, 8/11 (72.7%) eventually had live births. Aside from increased reporting of abnormal liver enzymes and cesarean deliveries, there was no significant difference in pregnancy outcomes before and after living liver donation. One-fifth of women who attempt pregnancy after liver donation reported infertility, and although the majority went on to successful live births, further exploration is needed to understand the contributing factors. Future research should continue to monitor this patient-centered outcome across a large cohort of donors.

Magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) is a viable alternative to liver biopsy for steatosis quantification in living liver donor transplantation

This study aimed to investigate whether magnetic resonance imaging-derived proton density fat fraction (MRI-PDFF) can be a viable noninvasive alternative to liver biopsy for the quantification of living liver donor steatosis. Hepatic steatosis for 143 donors was graded by MRI-PDFF. Study endpoints included liver volume regeneration in donors, recipient outcomes including length of hospital stay, deaths, primary non-function (PNF), early allograft dysfunction (EAD), and small for size syndrome (SFSS). Correlation between MRI-PDFF determined donor steatosis and endpoints were analyzed. Donors had lower steatosis grade than non-donors. Donor remnant liver regenerated to an average of 82% of pre-donation volume by 101 ± 24 days with no complications. There was no correlation between percent liver regeneration and steatosis severity. Among recipients, 4 underwent redo-transplantation and 6 died, with no association with degree of steatosis. 52 recipients (36%) fulfilled criteria for EAD (driven by INR), with no difference in hepatic steatosis between groups. MRI-PDFF reliably predicted donor outcomes. Living donors with no or mild steatosis based on MRI-PDFF (ie, <20%) and meeting other criteria for donation can expect favorable post-surgical outcomes, including liver regeneration. Recipients had a low rate of death or retransplantation with no association between mild hepatic steatosis and EAD.

Long-term impact and clinical significance of living donor liver transplantation with respect to donor liver restoration and spleen size: A prospective study

This study aimed to evaluate postoperative long-term liver restoration and splenic enlargement and their clinical significance in living donor liver transplantation. One hundred and sixteen donors who had donated livers more than 5 years previously accepted the invitation to participate in this study. The liver restoration rate and the splenic enlargement rate were calculated as the rate with respect to the original volume. The mean liver restoration rate was 0.99 ± 0.12 and older age was associated with a higher incidence for liver restoration rate <0.95 (P = .005), whereas type of donor operation was not. The donors with liver restoration rate <0.95 showed lower serum albumin levels than those with liver restoration rate ≥0.95. The mean splenic enlargement rate was 1.10 ± 0.16. Right lobe donors demonstrated higher splenic enlargement rate (1.14 ± 0.18) than left lobe/lateral segment donors (1.06 ± 0.13). In the donors with splenic enlargement rate ≥1.10, platelet count was not fully restored to the preoperative level. In conclusion, older age increases the risk for incomplete postoperative liver restoration, which may be associated with a decrease in albumin more than 5 years after donation. Right lobe donation poses a risk of splenic enlargement, which is associated with incomplete restoration of platelet count.

Automatic liver segmentation by integrating fully convolutional networks into active contour models

PURPOSE

Automatic and accurate three-dimensional (3D) segmentation of liver with severe diseases from computed tomography (CT) images is a challenging task. Fully convolutional networks (FCNs) have emerged as powerful tools for automatic semantic segmentation, with multiple potential applications in medical imaging. However, the use of a large receptive field and multiple pooling layers in the network leads to poor localization around object boundaries. The network usually makes pixel-wise prediction independently, making it difficult to respect local label consistency and enforce the smoothness of the object boundary.

METHODS

We have developed an automatic liver segmentation method based on a novel framework that integrates fully convolutional network predictions into active contour models (ACM). We use only a single network architecture to generate a pixel label map containing spatial regional information (foreground and background) as well as layered boundary information. We exploit the structured network outcome to define an external constraint force of active contour models. A unique property of the designed force is that both its strength and direction are adaptive to its position and relative distance to the object boundary. The resulting integrated active contour models have the advantages of incorporating both high-level and low-level image information simultaneously, while enforcing the smoothness of the contour. Because the external constraint force can push the evolving contour to the liver boundary and exists everywhere in the image domain, it allows us to place the initial contour far away from the liver boundary. It potentially allows us to control the evolution of the contour in order to preserve the topology of the liver.

RESULTS

We have trained and evaluated our model on 73 liver CT scans from a clinic study. The integrated ACM model yields mean dice coefficients (DICE) 95.8 ± 1.4 (%). Without further fine-tuning the network weights for two independent datasets, it yields mean DICE 96.2 ± 0.9 (%) for the SLIVER07 training dataset, and mean DICE 94.3 ± 2.7 (%) for the LiTS training dataset. In comparison with FCN alone model, the integrated ACM model yields improvements in terms of surface distance and DICE values for almost all the cases. Furthermore, the initialization of the active contour can be very far away from the liver boundary.

CONCLUSIONS

Experimental results for segmenting livers (with severe diseases on CT images resulting in shape and density abnormalities) have revealed that our proposed model improves segmentation results in comparison with FCN alone. Without further fine-tuning the network weights for two independent datasets, the model is capable of handling image variations from different datasets due to its inherent deformable nature. It is relatively easy to integrate more advanced (either existing or future) FCN architecture into our framework to further improve the segmentation performance.

Current Status of Living Donor Liver Transplantation in the United States

Adult-to-adult living donor liver transplantation (LDLT) was introduced in response to the shortage of deceased donor liver grafts. The number of adult living donor transplants is increasing due to improved outcomes and increasing need. Advantages of LDLT include optimization of the timing of transplant, better organ quality, and lower rates of recipient mortality compared to staying on the wait list for deceased donor liver transplant. Donor safety remains the major focus when considering LDLT. Recent advancements have supported the increased use of LDLT to help decrease wait list death and improve long-term survival of transplant recipients.

Low Preoperative Platelet Count Predicts Risk of Subclinical Posthepatectomy Liver Failure in Right Lobe Donors for Liver Transplantation

Living donor right hepatectomy (LDRH) is a common procedure in adult-to-adult living donor liver transplantation, but it is associated with a higher risk of posthepatectomy liver failure (PHLF) compared with left hepatectomy because of a smaller remnant. We identified risk factors for PHLF and other complications in LDRH, verified the appropriateness of the criteria, and explored the possibility of adjusting the minimum remnant liver volume (RLV) based on individual risk. Between October 2005 and November 2017, 254 donors undergoing LDRH at Kyoto University Hospital were enrolled. Clinical data were collected retrospectively. All complications were graded according to the Clavien-Dindo classification. No donors had grade 4 or 5 complications or clinically significant grade B or C PHLF. Grade A PHLF occurred in 30 donors (11.8%). Male sex (P = 0.01), lower preoperative platelet count (PLT; P = 0.01), higher prothrombin time-international normalized ratio (P = 0.03), higher total bilirubin (P = 0.01), smaller RLV (P = 0.03), and greater blood loss (P = 0.04) were associated with increased risk of PHLF in the univariate analysis, whereas PLT, RLV, and blood loss remained significant in the multivariate analysis. Grade 2 or 3 complications were observed in 32 (12.6%) donors. Higher body mass index (BMI; P = 0.002) and larger blood loss (P = 0.02) were identified as risk factors for complications (Clavien-Dindo grade ≥ 2) in univariate analysis. Only BMI remained significant in the multivariate analysis. In conclusion, LDRH is performed safely with acceptable morbidity under the current criteria. Minimum RLV may be marginally adjusted by PLT and reducing intraoperative blood loss minimizes PHLF risk. Liver Transplantation 00 000-000 2018 AASLD.

Liver atrophy and regeneration in noncirrhotic portal vein thrombosis: Effect of surgical shunts

The goal of the study is to characterize the relationship between portal vein thrombosis (PVT) and hepatic atrophy in patients without cirrhosis and the effect of various types of surgical shunts on liver regeneration and splenomegaly. Patients without cirrhosis with PVT suffer from presinusoidal portal hypertension, and often hepatic atrophy is a topic that has received little attention. We hypothesized that patients with PVT have decreased liver volumes, and shunts that preserve intrahepatic portal flow enhance liver regeneration. Sixty-four adult and pediatric patients with PVT who underwent surgical shunt placement between 1998 and 2011 were included in a retrospective study. Baseline liver volumes from adult patients were compared with standard liver volume (SLV) as well as a group of healthy controls undergoing evaluation for liver donation. Clinical assessment, liver function tests, and liver and spleen volumes from cross-sectional imaging were compared before and after surgery. A total of 40 patients received portal flow-preserving shunts (32 mesoportal and 8 selective splenorenal), whereas 24 received portal flow-diverting shunts (16 nonselective splenorenal and 8 mesocaval). Baseline adult liver volumes were 26% smaller than SLV (1248 versus 1624 cm³ ; P = 0.02) and 20% smaller than the control volumes (1248 versus 1552 cm³ ; P = 0.02). Baseline adult spleen volumes were larger compared with controls (1258 versus 229 cm³ ; P < 0.001). Preserving shunts were associated with significant increase in liver volumes (886 versus 1131 cm³ ; P = 0.01), whereas diverting shunts were not. Diverting shunts significantly improved splenomegaly. In conclusion, we have demonstrated that patients without cirrhosis with PVT have significant liver atrophy and splenomegaly. Significant liver regeneration was achieved after portal flow-preserving shunts. Liver Transplantation 24 881-887 2018 AASLD.

Status of Adult Living Donor Liver Transplantation in the United States: Results from the Adult-To-Adult Living Donor Liver Transplantation Cohort Study

This article reviews the Adult-to-Adult Living Donor Liver Transplant Cohort Study (A2ALL). The findings show that the number of adult-to-adult living donor liver transplants is consistently increasing. Living donor liver transplantation has an important benefit for patients with acute liver failure, does not compromise donor safety, and has lower rates of acute cellular rejection in biologically related donor and recipient. The conclusions from the A2ALL consortium have been critical in transplant advancement, supporting increased use to help decrease waitlist death and improve long-term survival of transplant recipients.

Longterm clinical and radiological follow-up of living liver donors

Although short-term risks of living donor hepatectomy have been well defined, little is known about the longterm impact. We aimed to perform a systematic follow-up to screen for unanticipated health consequences of liver donation. All donors who were more than 1 year from donation were invited for a systematic evaluation including physical and laboratory assessment, quality of life questionnaire, and magnetic resonance imaging (MRI)/magnetic resonance cholangiopancreatography (MRCP). Those unable to return were offered the questionnaire and laboratory assessment at home. Out of our total of 97 donors, 45 returned for a full assessment and 23 completed labs and survey locally (total n = 68; 70%) after a median of 5.5 years (1.5-10.9 years) after donation. The only laboratory abnormality was a significant decrease in platelet count (median 198 ×10(9) /L versus 224 ×10(9) /L before donation; P < 0.001), whereas 93% of patients were still above normal limits. No late biliary strictures or other structural abnormalities were found on MRI/MRCP. Liver regeneration was complete. Spleen volume did significantly increase (median 278 cm(3) versus 230 cm(3) before donation; P < 0.001) without resulting in lowered platelets (P = 0.73). The most common complaints were persistent incisional numbness and changed bowel habits. Seven donors (11%) reported problems obtaining insurance. The vast majority (97%) would have donated again. In conclusion, longterm outcome following liver donation appears satisfactory. None of our donors have developed occult biliary strictures, failure of regeneration, abnormal liver function, or other important health consequences after a median of 5.5 years from surgery. These findings can be used when counseling potential donors in the future. Liver Transplantation 22 934-942 2016 AASLD.

Living donor liver transplantation in the USA

Living donor liver transplant (LDLT) accounts for a small volume of the transplants in the USA. Due to the current liver allocation system based on the model for end-stage liver disease (MELD), LDLT has a unique role in providing life-saving transplantation for patients with low MELD scores and significant complications from portal hypertension, as well as select patients with hepatocellular carcinoma (HCC). Donor safety is paramount and has been a topic of much discussion in the transplant community as well as the general media. The donor risk appears to be low overall, with a favorable long-term quality of life. The latest trend has been a gradual shift from right-lobe grafts to left-lobe grafts to reduce donor risk, provided that the left lobe can provide adequate liver volume for the recipient.

Ad Integrum Functional and Volumetric Recovery in Right Lobe Living Donors: Is It Really Complete 1 Year After Donor Hepatectomy?

The partial liver's ability to regenerate both as a graft and remnant justifies right lobe (RL) living donor liver transplantation. We studied (using biochemical and radiological parameters) the rate, extent of, and predictors of functional and volumetric recovery of the remnant left liver (RLL) during the first year in 91 consecutive RL donors. Recovery of normal liver function (prothrombin time [PT] ≥70% of normal and total bilirubin [TB] ≤20 µmol/L), liver volumetric recovery, and percentage RLL growth were analyzed. Normal liver function was regained by postoperative day's 7, 30, and 365 in 52%, 86%, and 96% donors, respectively. Similarly, mean liver volumetric recovery was 64%, 71%, and 85%; whereas the percentage liver growth was 85%, 105%, and 146%, respectively. Preoperative PT value (p = 0.01), RLL/total liver volume (TLV) ratio (p = 0.03), middle hepatic vein harvesting (p = 0.02), and postoperative peak TB (p < 0.01) were predictors of early functional recovery, whereas donor age (p = 0.03), RLL/TLV ratio (p = 0.004), and TLV/ body weight ratio (p = 0.02) predicted early volumetric recuperation. One-year post-RL donor hepatectomy, though functional recovery occurs in almost all (96%), donors had incomplete restoration (85%) of preoperative total liver volume. Modifiable predictors of regeneration could help in better and safer donor selection, while continuing to ensure successful recipient outcomes.

Defining long-term outcomes with living donor liver transplantation in North America

OBJECTIVES

To compare long-term survival of living donor liver transplant (LDLT) at experienced transplant centers with outcomes of deceased donor liver transplant and identify key variables impacting patient and graft survival.

BACKGROUND

The Adult-to-Adult Living Donor Liver Transplantation Cohort Study is a prospective multicenter National Institutes of Health study comparing outcomes of LDLT and deceased donor liver transplant and associated risks.

METHODS

Mortality and graft failure for 1427 liver recipients (963 LDLT) enrolled in the Adult-to-Adult Living Donor Liver Transplantation Cohort Study who received transplant between January 1, 1998, and January 31, 2014, at 12 North American centers with median follow-up 6.7 years were analyzed using Kaplan-Meier and multivariable Cox models.

RESULTS

Survival probability at 10 years was 70% for LDLT and 64% for deceased donor liver transplant. Unadjusted survival was higher with LDLT (hazard ratio = 0.76, P = 0.02) but attenuated after adjustment (hazard ratio = 0.98, P = 0.90) as LDLT recipients had lower mean model for end-stage liver disease (15.5 vs 20.4) and fewer received transplant from intensive care unit, were inpatient, on dialysis, were ventilated, or with ascites. Posttransplant intensive care unit days were less for LDLT recipients. For all recipients, female sex and primary sclerosing cholangitis were associated with improved survival, whereas dialysis and older recipient/donor age were associated with worse survival. Higher model for end-stage liver disease score was associated with increased graft failure. Era of transplantation and type of donated lobe did not impact survival in LDLT.

CONCLUSIONS

LDLT provides significant long-term transplant benefit, resulting in transplantation at a lower model for end-stage liver disease score, decreased death on waitlist, and excellent posttransplant outcomes. Recipient diagnosis, disease severity, renal failure, and ages of recipient and donor should be considered in decision making regarding timing of transplant and donor options.Clinical Trials ID: NCT00096733.